Functional status impairment is associated with unplanned readmissions

Objective: To determine whether functional status on admission to a Comprehensive Integrated Inpatient Rehabilitation Program (CIIRP) is associated with unplanned readmission to acute care.

Design: Retrospective cohort study.

Setting: Academic hospital-based CIIRP.

Participants: Consecutive patients (N=1515) admitted to a CIIRP between January 2009 and June 2012.

Interventions: Patients' functional status, the primary exposure variable, was assessed using tertiles of the total FIM score at CIIRP admission, with secondary analyses using the FIM motor and cognitive domains. A propensity score, consisting of 25 relevant clinical and demographic variables, was used to adjust for confounding in the analysis.

Main outcome measures: Readmission to acute care was categorized as (1) readmission before planned discharge from the CIIRP, (2) readmission within 30 days of discharge from the CIIRP, and (3) total readmissions from both groups, with total readmissions being the a priori primary outcome.

Results: Among the 1515 patients, there were 347 total readmissions. Total readmissions were significantly associated with FIM scores, with adjusted odds ratios (AORs) and 95% confidence intervals (CIs) for the lowest and middle FIM tertiles versus the highest tertile (AOR=2.6; 95% CI, 1.9-3.7; P<.001 and AOR=1.7; 95% CI, 1.2-2.4; P=.002, respectively). There were similar findings for secondary analyses of readmission before planned discharge from the CIIRP (AOR=3.5; 95% CI, 2.2-5.8; P<.001 and AOR=2.1; 95% CI, 1.3-3.5l P=.002, respectively), and a weaker association for readmissions after discharge from the CIIRP (AOR=1.6; 95% CI, 1.0-2.4; P=.047 and AOR=1.3; 95% CI, 0.8-1.9; P=.28, respectively). The FIM motor domain score was more strongly associated with readmissions than the FIM cognitive score.

Conclusions: Functional status on admission to the CIIRP is strongly associated with readmission to acute care, particularly for motor aspects of functional status and readmission before planned discharge from the CIIRP. Efforts to reduce hospital readmissions should consider patient functional status as an important and potentially modifiable risk factor.